<?php
/**
 * @file classes/components/form/context/PKPThemeForm.php
 *
 * Copyright (c) 2014-2021 Simon Fraser University
 * Copyright (c) 2000-2021 John Willinsky
 * Distributed under the GNU GPL v3. For full terms see the file docs/COPYING.
 *
 * @class PKPThemeForm
 *
 * @ingroup classes_controllers_form
 *
 * @brief A form for selecting a theme and theme options. Expects to be attached
 *  to a <theme-form> element in the UI.
 *
 * This form works similarly to other form components, except that it keeps a
 * separate store of fields for each theme's options. Only the active theme's
 * fields are loaded into $this->fields. The <theme-form> UI component chooses
 * which fields to display as the theme selection is changed.
 */

namespace PKP\components\forms\context;

use APP\core\Application;
use PKP\components\forms\FieldSelect;
use PKP\components\forms\FormComponent;
use PKP\plugins\PluginRegistry;
use PKP\plugins\ThemePlugin;

class PKPThemeForm extends FormComponent
{
    public const FORM_THEME = 'theme';
    public $id = self::FORM_THEME;
    public $method = 'PUT';

    /** @var array A key/value store of theme option fields, keyed by theme name */
    public $themeFields = [];

    /**
     * Constructor
     *
     * @param string $action URL to submit the form to
     * @param array $locales Supported locales
     * @param \PKP\context\Context|null $context Journal/Press to change settings for, or null
     *  to change settings for the Site
     */
    public function __construct($action, $locales, $context = null)
    {
        $this->action = $action;
        $this->locales = $locales;

        if (!empty($context)) {
            $activeTheme = $context->getData('themePluginPath');
            $contextId = $context->getId();
        } else {
            $activeTheme = Application::get()->getRequest()->getSite()->getData('themePluginPath');
            $contextId = \PKP\core\PKPApplication::SITE_CONTEXT_ID;
        }

        $themes = $themeOptions = [];
        /** @var ThemePlugin[] */
        $plugins = PluginRegistry::loadCategory('themes', true);
        foreach ($plugins as $plugin) {
            $themes[] = [
                'value' => $plugin->getDirName(),
                'label' => htmlspecialchars($plugin->getDisplayName()),
            ];
        }

        $this->addField(new FieldSelect('themePluginPath', [
            'label' => __('manager.setup.theme'),
            'description' => __('manager.setup.theme.description'),
            'options' => $themes,
            'value' => $activeTheme,
        ]));

        // Add theme options for each theme
        foreach ($plugins as $plugin) {
            // Re-run the init functions for each theme so that any theme options
            // are set up. Because this is run after PluginRegistry::loadCategory(),
            // the scripts and styles won't actually be registered against the
            // template manager. However, if PluginRegistry::loadCategory() is called
            // again for the themes category, it can cause scripts and styles to be
            // overwritten by inactive themes.
            $plugin->init();
            $themeOptions = $plugin->getOptionsConfig();
            if (empty($themeOptions)) {
                continue;
            }
            $themeOptionValues = $plugin->getOptionValues($contextId);
            foreach ($themeOptions as $optionName => $optionField) {
                $optionField->value = $themeOptionValues[$optionName] ?? null;
                $this->addThemeField($plugin->getDirName(), $optionField);
            }
        }
    }

    /**
     * Add a form field that should only appear when a particular theme is
     * selected
     *
     * @param string $theme The theme's base plugin path
     * @param \PKP\components\forms\Field $field
     * @param array $position [
     *
     *  @option string One of `before` or `after`
     *  @option string The field to position it before or after
     * ]
     *
     * @return FormComponent
     */
    public function addThemeField($theme, $field, $position = [])
    {
        if (empty($position)) {
            if (!isset($this->themeFields[$theme])) {
                $this->themeFields[$theme] = [];
            }
            $this->themeFields[$theme][] = $field;
        } else {
            $this->themeFields[$theme] = $this->addToPosition($position[1], $this->themeFields[$theme], $field, $position[0]);
        }
        return $this;
    }

    /**
     * @copydoc FormComponent::getConfig()
     */
    public function getConfig()
    {
        // Add the active theme's option fields to the fields array
        $activeThemeField = array_filter($this->fields, function ($field) {
            return $field->name === 'themePluginPath';
        });
        $activeTheme = $activeThemeField[0]->value;
        if (!empty($this->themeFields[$activeTheme])) {
            $this->fields = array_merge($this->fields, $this->themeFields[$activeTheme]);
        }

        $config = parent::getConfig();

        // Set up field config for non-active fields
        if (!$this->groups) {
            $this->addGroup(['id' => 'default']);
            $this->fields = array_map(function ($field) {
                $field->groupId = 'default';
                return $field;
            }, $this->fields);
        }
        $defaultGroupId = $this->groups[0]['id'];
        $config['themeFields'] = array_map(function ($themeOptions) use ($defaultGroupId) {
            return array_map(function ($themeOption) use ($defaultGroupId) {
                $field = $this->getFieldConfig($themeOption);
                $field['groupId'] = $defaultGroupId;
                return $field;
            }, $themeOptions);
        }, $this->themeFields);

        return $config;
    }
}
